//////////////////////////////////////////////////
// JIST (Java In Simulation Time) Project
// Timestamp: <Placement.java Tue 2004/04/06 11:31:11 barr pompom.cs.cornell.edu>
//

// Copyright (C) 2004 by Cornell University
// All rights reserved.
// Refer to LICENSE for terms and conditions of use.

package jist.swans.field;

import jist.swans.misc.Location;
import jist.swans.Constants;

/** 
 * Interface of all initial placement models.
 *
 * @author Rimon Barr &lt;barr+jist@cs.cornell.edu&gt;
 * @version $Id: Placement.java,v 1.1 2007/04/09 18:49:27 drchoffnes Exp $
 * @since SWANS1.0
 */

public interface Placement
{

  /**
   * Return location of next node.
   *
   * @return location of next node
   */
  Location getNextLocation();


  //////////////////////////////////////////////////
  // random placement model
  //

  /**
   * Random (uniform) placement.
   */
  public static class Random implements Placement
  {
    /** placement boundaries. */
    private float x, y;

    /**
     * Initialize random placement model.
     *
     * @param x x-axis upper limit
     * @param y y-axis upper limit
     */
    public Random(float x, float y)
    {
      init(x, y);
    }

    /**
     * Initialize random placement.
     *
     * @param loc upper limit coordinate
     */
    public Random(Location loc)
    {
      init(loc.getX(), loc.getY());
    }

    /**
     * Initialize random placement.
     *
     * @param field field dimensions string
     */
    public Random(String field)
    {
      String[] data = field.split("x|,");
      if(data.length!=2) throw new IllegalArgumentException("invalid format, expected i,j");
      init(Float.parseFloat(data[0]), Float.parseFloat(data[1]));
    }

    /**
     * Initialize random placement.
     *
     * @param x field x-dimension (in meters)
     * @param y field y-dimension (in meters)
     */
    private void init(float x, float y)
    {
      this.x = x;
      this.y = y;
    }

    //////////////////////////////////////////////////
    // Placement interface
    //

    /** {@inheritDoc} */
    public Location getNextLocation()
    {
      return new Location.Location2D(
          Constants.random.nextFloat()*x,
          Constants.random.nextFloat()*y);
    }

  } // class: Random


  //////////////////////////////////////////////////
  // grid placement model
  //

  /**
   * Placement along a regular grid.
   */
  public static class Grid implements Placement
  {
    /** field dimensions. */
    private float fieldx, fieldy;
    /** node placement array dimensions. */
    private int nodex, nodey;
    /** number of nodes already placed. */
    private long i;

    /**
     * Initialize grid placement model.
     *
     * @param loc field dimensions (in meters)
     * @param nodex number of nodes in x-dimension
     * @param nodey number of nodes in y-dimension
     */
    public Grid(Location loc, int nodex, int nodey)
    {
      init(loc.getX(), loc.getY(), nodex, nodey);
    }

    /**
     * Initialize grid placement model.
     *
     * @param loc field dimensions (in meters)
     * @param s node configuration string
     */
    public Grid(Location loc, String s)
    {
      init(loc, s);
    }

    /**
     * Initialize grid placement model.
     *
     * @param field field dimensions string
     * @param nodes node configuration string
     */
    public Grid(String field, String nodes)
    {
      init(field, nodes);
    }

    /**
     * Initialize grid placement model.
     *
     * @param field field dimensions string
     * @param nodes node configuration string
     */
    private void init(String field, String nodes)
    {
      String[] data = field.split("x|,");
      if(data.length!=2) throw new IllegalArgumentException("invalid format, expected i,j");
      init(new Location.Location2D(Float.parseFloat(data[0]), Float.parseFloat(data[1])), nodes);
    }

    /**
     * Initialize grid placement model.
     *
     * @param loc field dimensions (in meters)
     * @param s node configuration string
     */
    private void init(Location loc, String s)
    {
      String[] data = s.split("x|,");
      if(data.length!=2) throw new IllegalArgumentException("invalid format, expected i,j");
      init(loc.getX(), loc.getY(), Integer.parseInt(data[0]), Integer.parseInt(data[1]));
    }

    /**
     * Initialize grid placement model.
     *
     * @param fieldx field x-dimension (in meters)
     * @param fieldy field y-dimension (in meters)
     * @param nodex number of nodes in x-dimension
     * @param nodey number of nodes in y-dimension
     */
    private void init(float fieldx, float fieldy, int nodex, int nodey)
    {
      this.fieldx = fieldx;
      this.fieldy = fieldy;
      this.nodex = nodex;
      this.nodey = nodey;
      i = 0;
    }

    //////////////////////////////////////////////////
    // Placement interface
    //

    /** {@inheritDoc} */
    public Location getNextLocation()
    {
      if(i/nodex==nodey) throw new IllegalStateException("grid points exhausted");
      Location l = new Location.Location2D(
          (i%nodex)*fieldx/nodex, (i/nodex)*fieldy/nodey);
      i++;
      return l;
    }

  } // class: Grid

} // interface: Placement

